Typical metal oxide semiconductor transistors are formed with a gate region between doped active regions. The doped active regions are typically designated as a source region and a drain region. Because the source drain regions of the transistor are often formed to be identical, and because the source drain regions may switch during different operations between functioning as a source region and functioning as a drain region, the source drain regions are referred to collectively herein, rather than as either a separate source region or a separate drain region.
For metal oxide semiconductor types of devices, the source drain regions are typically electrically isolated from the gate region. This electrical isolation is often provided by an electrically nonconductive layer, such as an oxide. The electrically nonconductive layer typically underlies the gate region, and is often called a gate oxide. The gate region may also have electrically nonconductive spacers formed all around the circumference of the gate region. The electrically nonconductive spacers are also often formed of oxide, and thus are often referred to as spacer oxide. For the specific case in which the integrated circuit is formed in a silicon substrate, a silicon oxide, such as silicon dioxide, is often used to form the gate oxide and the spacer oxide.
In many applications, the source drain regions and the gate region of the transistor are not electrically connected one to another in near proximity to the transistor. In other words, two or more of the three elements may be electrically connected in some manner through other elements of the integrated circuit, but they are not directly electrically connected one to another, but rather are directly electrically connected to other elements within the integrated circuit.
However, in other applications it is desirable that two of the elements be directly electrically connected one to the other. For example, in many applications it is desirable that one of the source drain regions be directly electrically connected to the gate region. When one source drain region is directly electrically connected to the gate region of the same transistor, the electrical connection is called a local interconnect.
Current methods for forming local interconnects tend to require many processing steps. Additionally, local interconnects formed by current processes tend to be relatively large structures that may extend through several mask layers of the integrated circuit. What is needed, therefore, is an electrical interconnect structure for an integrated circuit, and a method for forming the electrical interconnect.